Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20170927a' into...

[qemu.git] / migration / postcopy-ram.h

diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 4c25f03be2b0500698ac42b41ec2fc36a16a17f5..587a8b86a799d0cee367e9892d2b1e8bcc34815c 100644 (file)
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -14,7 +14,7 @@
 #define QEMU_POSTCOPY_RAM_H
 
 /* Return true if the host supports everything we need to do postcopy-ram */
-bool postcopy_ram_supported_by_host(void);
+bool postcopy_ram_supported_by_host(MigrationIncomingState *mis);
 
 /*
  * Make all of RAM sensitive to accesses to areas that haven't yet been written
@@ -81,6 +81,28 @@ int postcopy_place_page(MigrationIncomingState *mis, void *host, void *from,
 int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
                              size_t pagesize);
 
+/* The current postcopy state is read/set by postcopy_state_get/set
+ * which update it atomically.
+ * The state is updated as postcopy messages are received, and
+ * in general only one thread should be writing to the state at any one
+ * time, initially the main thread and then the listen thread;
+ * Corner cases are where either thread finishes early and/or errors.
+ * The state is checked as messages are received to ensure that
+ * the source is sending us messages in the correct order.
+ * The state is also used by the RAM reception code to know if it
+ * has to place pages atomically, and the cleanup code at the end of
+ * the main thread to know if it has to delay cleanup until the end
+ * of postcopy.
+ */
+typedef enum {
+    POSTCOPY_INCOMING_NONE = 0,  /* Initial state - no postcopy */
+    POSTCOPY_INCOMING_ADVISE,
+    POSTCOPY_INCOMING_DISCARD,
+    POSTCOPY_INCOMING_LISTENING,
+    POSTCOPY_INCOMING_RUNNING,
+    POSTCOPY_INCOMING_END
+} PostcopyState;
+
 /*
  * Allocate a page of memory that can be mapped at a later point in time
  * using postcopy_place_page
@@ -88,4 +110,8 @@ int postcopy_place_page_zero(MigrationIncomingState *mis, void *host,
  */
 void *postcopy_get_tmp_page(MigrationIncomingState *mis);
 
+PostcopyState postcopy_state_get(void);
+/* Set the state and return the old state */
+PostcopyState postcopy_state_set(PostcopyState new_state);
+
 #endif